// stylus: @import 'xx.styl' ; 代码里直接调用xx()
// scss:   @import 'xx.scss' ; 代码里直接调用$xx
ellipsis()
  overflow:  hidden
  text-overflow: ellipsis
  white-space: nowrap

ellipsis2()
  text-overflow: -o-ellipsis-lastline
  overflow: hidden
  text-overflow: ellipsis
  display: -webkit-box
  -webkit-line-clamp: 2
  -webkit-box-orient: vertical

clearBoth()
  clear: both

back()
  color: green